1. Technical Field
This invention relates to hinge mechanisms and, more particularly, to a hood tilt hinge operative to permit the forward tilting of the hood or front end upwards and outwards from the vehicle's main body, the hinge assembly including upper and lower generally cylindrical hinge sections and an offset hinge bracket pivotably connecting the two hinge sections such that the upper hinge section may be tilted forwardly relative to the lower hinge section with the hinge bracket providing stop means for preventing rotation of the upper hinge section.
2. Description of the Prior Art
On oversized or "monster" trucks, the engine of the truck as in standard trucks is covered by a hood and surrounded by front quarter panels. While access to the engine compartment may be gained through operation of a standard hood opening arrangement, however, due to the height of the "monster" trucks, it is preferred that the vehicle include a tilt-forward hood which raises the hood and front quarter panels to allow access to the engine compartment. Most trucks which include tilt-forward hoods support these hoods either by concealed hinges or exposed hinges. Exposed hinges include arrangements such as piano-type hinges mounted on the bumper structure to allow the front of the body to tilt forward. Concealed hinges are hidden within the hood and cannot be seen from the outside of the vehicle when the hood is closed. With each type of hinge, however, the main purpose is to allow access to the engine compartment.
Examples of exposed hinges are found throughout the prior art and include such devices as found in Miller, et al., U.S. Pat. No. 4,281,733, and Lundelius, U.S. Pat. No. 1,598,868. These devices are similar to one another and include the basic features of the exposed hinge, namely that the hinge is positioned generally adjacent the front bumper with the lower part of the hinge mounted to the main truck frame and the upper part of the hinge mounted to the hood itself. The hinge body itself is exposed just above the front bumper of the truck. Miller and Lundelius each also include tilt restraint devices which, in the case of both devices, is an hydraulic cylinder.
There are several disadvantages in the use of exposed hinges. These include the problem that exposed hinges will receive more wear and tear due to exposure to the environment and thus may become corroded or have their efficiency impaired due to grime or debris entering the hinge thus rendering it difficult to tilt the hood as designed. Also, the external appearance of the exposed hinge may be unsightly, unless steps are taken to design the vehicle's exterior styling so that the hinge blends in with it. Of course, depending on the size and shape of the hinge, this may not always be possible. Furthermore, none of the exposed hinges found in the prior art include built-in damping or stopping mechanisms to prevent overrotation of the hood. Therefore, additional stopping mechanisms are needed to prevent overrotation, increasing the complexity of the hinge arrangement and thus adding more elements which can fail to prevent the hinge from operating as designed. There is therefore a need for a hinge which will address and solve those problems found in the art of exposed hinges.
Another type of hinge commonly used for the tilting of hoods is the concealed hinge, examples of which are found in the prior art in such devices as shown in Peterson, U.S. Pat. No. 2,254,088 and Oen, U.S. Pat. No. 4,658,470. While both these devices disclose concealed hinges, it is Oen which is specifically directed to a truck having a tilt-forward hood. Generally, concealed hinges are mounted on a vehicle with the lower part of the hinge mounted to the frame of the vehicle and the upper part of the hinge mounted to the hood itself, the hinge being positioned generally adjacent the front bumper of the vehicle. However, unlike the exposed hinges, the concealed hinge is positioned inside the hood itself and thus is not visible when the hood is in the closed position. One of the disadvantages of the devices found in the prior art is that they tend to include additional moving parts and adjustment mechanisms beyond those which are strictly needed for operation of the concealed hinge. For example, Peterson includes a spring-loaded offset mechanism to allow the hood to move upwardly and forwardly such that rotation of the hood about the hinge is permitted. Oen, on the other hand, does not include an offset mechanism but does include an adjustment mechanism consisting of a threaded bolt for adjusting the position of the hinge. Obviously, with the addition of adjustment and offset devices to the hinge, additional potential problems are introduced, including malfunction of the adjustment device of Oen and the potential of the offset mechanism of Peterson to become stuck thus preventing the hood from being lifted. Furthermore, the construction characteristics found in the prior art may not be suitable for heavy duty vehicles which include heavy-hooded units or the like. Since oversized or "monster" trucks are often used in extremely muddy conditions, a sturdy and mechanically simple hinge assembly is preferable to those somewhat complex devices found in the prior art. There is therefore a need for a mechanically simple concealed hinge for use in oversized or "monster" trucks.
As stated previously, many of the hinges found in the prior art require a simple stop mechanism to prevent overrotation of the hood. It should be noted that the additional stop mechanisms shown in the prior art will tend to interfere with access to the engine compartment, thus reducing accessability to the engine department. There is therefore a need for a concealed hood tilt hinge which includes a stop mechanism built into the hinge itself.
Therefore, an object of the present invention is to provide an improved hood tilt hinge assembly.
Another object of the present invention is to provide a hood tilt hinge assembly which includes upper and lower hinge sections connected to one another by a hinge bracket, the hinge bracket including offset upper and lower bracket cylinders which are pivotably connected to the upper and lower hinge sections to allow the upper hinge section to tilt forwardly relative to the lower hinge section.
Another object of the present invention is to provide a hood tilt hinge assembly in which the hinge bracket includes a plate which, when pivoted a predetermined distance, will contact a section of the lower hinge section wall structure thus preventing further movement of the upper hinge section and acting as a stop mechanism.
Another object of the present invention is to provide a hood tilt hinge assembly which is concealed by the hood itself when the hood is in the closed position so that the hinge does not degrade the appearance of the vehicle on which it is placed.
Another object of the present invention is to provide a hood tilt hinge assembly which does not include superfluous adjustment or offset mechanisms which may render the hinge more vulnerable to breakdowns.
Another object of the present invention is to provide a hinge assembly which may be used as an artificial joint replacement hinge or the like.
Finally, an object of the present invention is to provide a hood tilt hinge assembly which is relatively simple to manufacture and which is safe and durable in use.